For the inexpensive mass production of molded parts by injection molding, in particular of plastics molded parts, injection-molding machines are used, having an injection unit, designed for compounding the raw material and injecting the injection-molding material under pressure into an injection-molding tool, and a clamping unit, receiving the injection-molding tool and intended for opening and closing. The injection unit generally has a screw, which is rotatably guided in a cylinder and has a pellets inlet in the rear region and a machine nozzle at the front, free end. The injection-molding material melted in the screw is injected into the injection-molding tool through the machine nozzle. The clamping unit has a nozzle-side platen, which is arranged perpendicularly on a machine frame and carries a nozzle-side tool half. The clamping unit also has an opposite movable platen, which is generally hydraulically movable in the direction of the fixed platen and carries an ejector-side tool half of the injection-molding tool. The machine space may also have a further fixed end plate, wherein a closing actuator, such as for example at least one hydraulic cylinder, is present between the end plate and the movable platen for opening and closing the movable platen.
Thus, an individualized injection-molding tool with individualized cavities and an individualized ejector mechanism is required for each molded part.
U.S. Pat. No. 7,204,685 B1 proposes for the high-speed and cost-effective production of individualized injection-molding tools a modular injection-molding tool in which, instead of monolithic tool plates, frame plates for receiving various mold inserts are provided. The mold inserts have individualized cavities and individualized ejector elements adapted thereto. The two halves of a mold insert are handled separately from one another and, during modification, are connected to the respective nozzle-side or ejector-side tool half.
In a corresponding way, such modular mold inserts are also described in U.S. Pat. No. 4,202,522 A and U.S. Pat. No. 3,871,611 A as well as in WO 00/38899 A1.
DE 10 2005 023 147 A1 describes a mold tool for producing injection-molded plastics parts, comprising a cavity, which can be connected to a plastics injection nozzle, and comprising coolant guides and tool parts comprising an ejector unit, individual parts of which can be fixed such that they can be detached from one another. The mold tool is designed as a modular tool for a master tool standardized on the basis of predeterminable parameters. The master tool has standardized attaching and connecting elements. The mold tool has at least one mold insert, which is adapted to the standardized attaching and connecting elements, can be detachably connected to the master mold and has an individualized cavity.